OTHER THEORIES OF SPECIES-FORMING. 229 



5 Weismann, A., "On Germinal Selection as a Source of Definite 

 Variation," trans. McCormack, p. 3, 1896. 



6 I quote from Morgan, "Evolution and Adaptation," pp. 165-166, 

 1903, the following special protest against the means of escape from 



ur ... a tight place which Weismann has taken advantage of 



Morgan s criti- 

 cism of Weis- in his dilemma: "Thus Weismann has piled up one 



mann's method hypothesis on another as though he could save the 

 of argument. integrity of the theory of natural selection by adding 

 new speculative matter to it. The most unfortunate feature is that 

 the new speculation is skilfully removed from the field of verifica- 

 tion, and invisible germs whose sole functions are those which 

 Weismann's imagination bestows on them, are brought forward 

 as though they could supply the deficiencies of Darwin's theory. 

 This is, indeed, the old method of the philosophisers of nature. An 

 imaginary system has been invented which attempts to explain all 

 difficulties, and if it fails, then new inventions are to be thought 

 of. Thus we see where the theory of the selection of fluctuating 

 germs has led one of the most widely known disciples of the Dar- 

 winian theory. 



"The worst feature of the situation is not so much that Weismann 

 has advanced new hypotheses unsupported by experimental evi- 

 dence, but that the speculation is of such a kind that it is, from its 

 very nature, unverifiable, and therefore useless. Weismann is mis- 

 taken when he assumes that many zoologists object to his methods 

 because they are largely speculative. The real reason is that the 

 speculation is so often of a kind that cannot be tested by observa- 

 tion or by experiment." 



7 Roux, W., "Der Kampf der Theile im Organismus," 1881. 



B Baldwin, J. Mark, "A New Factor in Evolution." Amer. Nat., 

 Vol. XXX, pp. 441 ff., 1896; see also the same author's "Develop- 

 Keferences to ment and Evolution," chap, viii, 1902 ; in the appen- 

 discussions of dices of this book is given a detailed history of the 

 orthoplasy. independent formulation of the theory of "Organic 



Selection or Orthoplasy," by Baldwin, Osborn, and Morgan. 



8 Osborn, H. F., "A Mode of Evolution requiring neither Natural 

 Selection nor the Inheritance of Acquired Characters," Trans. New 

 York Acad. Sci., pp. 141-148, 1896; also Science, April 3. 1896; also 

 Amer. Nat., Nov., 1897. From this last reference I quote the 

 following concise statement of the theory : "This hypothesis as it 

 appears to myself is, briefly, that ontogenic adaptation is of a very 

 profound character ; it enables animals and plants to survive very 

 critical changes in their environment. Thus all the individuals of 

 a race are similarly modified over such long periods of time that, 

 very gradually, congenital variations which happen to coincide with 



